SOUTH FLORIDA -- At least by one key measure, Florida Bay water quality took a turn for the worse between 2008 and 2013, according to a status report on the Everglades ecosystem released last week by the South Florida Water Management District and the U.S. Army Corps of Engineers.

Salt levels, which scientists say must go down if the bay and its vital seagrass communities are going to flourish, instead rose between May 1, 2008, and April 30, 2013, according to the report. In a related development, seagrass diversity within the bay declined during that period, the report found.

Both pieces of bad news were caused largely by drier-than-normal weather over the five-year period. As a result, less fresh water flowed through the South Florida network of manmade canals and natural sloughs into Florida Bay.

Increasing the flow of clean fresh water into the southern Everglades and Florida Bay is one of the main goals of Everglades restoration.

Ominously, the report notes that the current pattern of seagrass distribution within Florida Bay is similar to patterns seen in 1984, just a few years before a mass seagrass die-off of approximately 40,000 acres that began in 1987. That die-off fueled a sequence of algae blooms so bad that fishing guides and scientists still remember the late 1980s and early '90s as a period in which the health of Florida Bay collapsed.

Scientists says the recent study, which is required as part of the joint state/federal $20 billion Comprehensive Everglades Restoration Plan, points to the importance of moving forward faster with restoration.

"I think it shows the bay is not healing itself," said Tom Van Lendt, a hydrologist for the Everglades Foundation.

The study, which also analyzed the health of other parts of the Everglades, from Lake Okeechobee south to mainland Everglades National Park, didn't include much data on the impact of the $26 million C-111 canal and water retention project. Designed to bring more freshwater into central Florida Bay and its main natural feeder, Taylor Slough, that project went online only in time for the fifth and final year included in the recent report.

But the authors did capture hydrological improvements in northern Taylor Slough, along the east side of Everglades National Park, where a restoration project was concluded in 2009.

"If we just keep the process going, we should see the start of progress in Florida Bay," said Bob Johnson, who heads the South Florida Natural Resources Center for Everglades National Park, and whose staff helped put the study together.

Though the five-year period captured in the study was cumulatively drier than normal, 2010 was a relatively wet year, Johnson said. During that particular 12-month cycle, Florida Bay's seagrass showed signs of improvement.

The ability of seagrass to recover quickly could be one positive note for the bay, he added, since more restoration projects that will impact the southern Everglades and Florida Bay are scheduled to become fully operational in 2016.

Van Lendt, though, noted that it's going to be harder to know exactly what changes are occuring in the 850-square-mile estuary at the tip of the Everglades. That's because budget cuts have forced federal and state Everglades restoration monitors to abandon various data collection programs.

For example, the report notes, restoration scientists are no longer tracking shrimp densities in Florida Bay or crocodile populations in the southern Florida coastal region.